In the semiconductor industry, there are a host of devices and methods in which a calibration of two surfaces to one another is of great importance. The surfaces are generally structured surfaces whose structures must be aligned to one another. In all methods that undertake these calibrations, it would be desirable for errors in alignment, especially wedge errors, such as deviations in the angular position of the two opposing surfaces that are to be aligned, to be minimized or largely precluded. Ideally, the surfaces of the substrates are to be aligned exactly parallel to one another in one end position, for example, in embossing a microlens or in producing a mask in the lithography method. In the example of microsystems engineering, and particularly, in the production of microlenses that must become smaller and at the same time more accurate as optical lenses due to the miniaturization pressure in the semiconductor industry, the aforementioned errors have an especially drastic effect.
Furthermore, it is especially important that the optical axis of the microlens does not have any alignment errors that are caused especially by wedge errors. Microlenses are often stacked on top of one another so that the wedge errors are correspondingly exacerbated, and the image quality suffers accordingly.
Furthermore, efforts are aimed at minimizing the scrap in the mass production of microlenses.
The aforementioned wedge error arises due to mis-positioning of the embossing substrates to one another or mis-positioning of the retaining systems that accommodate the embossing substrates to one another in the end position where the embossing material is cured. The positioning of the embossing substrate is decisive for the production of the components to be embossed, especially microlenses.
The wedge error has been reduced in the past by parallel alignment of the retaining system as accurately as possible before the retaining systems close the gap between the surfaces of the substrates and before the actual embossing process in which the substrates are moved toward one another in the direction of translation.
The present invention provides a device and a method wherein alignment errors in the alignment of two spaced substrates can be minimized, and as a result, the quality of the products to be produced increases and the production costs are drastically reduced.
The foregoing is achieved with the features of the claims. Further advantageous developments of the invention are indicated in the dependent claims. All combinations of at least two of the features indicated in the specification, the claims and/or FIG. 1 also fall within the framework of the invention. At the indicated value ranges, values within the above-mentioned limits will also be disclosed as boundary values (limits) and will be claimed in any combination.